Motor-pump unit

ABSTRACT

The invention relates to a motor/pump unit;  
     with an electric motor;  
     with a pump.  
     The invention encompasses the following characterizing features:  
     the pump is concentrically surrounded by the rotor/stator of the motor;  
     the rotor of the electric motor is U-shaped, viewed in an axial section;  
     the cross-piece of the “U”, in the region of the common axis, is provided with an interior toothing;  
     the shaft of the pump displays a pinion that meshes with the interior toothing of the crosspiece of the “U”.

[0001] The invention relates to a motor/pump unit, in which an electric motor and a pump are structurally unified with each other. In this, the rotor/stator of the motor surrounds the pump.

[0002] DE 195 38 278 A1 describes one such.motor/pump unit. Here, the rotor of the electric motor is simultaneously the pump wheel of the pump.

[0003] EP 0 611 887 A1 describes a motor/pump unit. Here, although the rotor is a independent component, nevertheless it is attached to the cylinder block of a reciprocating pump in a rotationally-fixed manner.

[0004] Units of this design have the great advantage that they claim only a minimal amount of space. However, they are still capable of being improved.

[0005] The invention is based on the task of improving still further a motor/pump unit of the mentioned design, in particular with respect to the production cost and the space requirement.

[0006] This task is accomplished through the features of claim 1.

[0007] Accordingly, the rotor of the electric motor, viewed in an axial section, is U-shaped. Here, the cross-piece of the “U” is provided, in the region of the axis of the unit, with an interior toothing, and the drive shaft of the pump with a corresponding pinion, so that the interior toothing and the pinion mesh with each other.

[0008] Different types of electric motors come into consideration, for example asynchronous motors, reluctance motors, or so-called short-circuit rotors.

[0009] Likewise, the most various types of pumps come into consideration. Especially advantageous is the application of the invention with inner gear pumps.

[0010] The pump forms in this case a completely independent, self-sufficient unit. It can be produced separately, tested separately, and be installed completely into the space enclosed by the stator of the electric motor.

[0011] Here, it is possible to support the rotor of the electric motor on the housing of the inner gear pump.

[0012] The invention is illustrated by means of the drawings. Represented in them are the following particulars:

[0013] The motor/pump unit comprises an electric motor 1 with a sheet-metal stator package 1.1, a winding 1.2, and a rotor 1.3.

[0014] It comprises further an inner gear pump 2. This displays a pinion 2.1, an eccentric hollow wheel 2.2 opposite this, as well as a pinion shaft 2.3. The pinion shaft 2.3 is seated in lateral discs 2.4, 2.5. In the present case, provision is made for slide bearings 2.4.1, 2.5.1.

[0015] The two elements motor and pump are enclosed by a common housing 3. Located in the housing is an intake 3.1 as well as an outlet 3.2 for the medium to be pumped.

[0016] According to the invention, the rotor 1.3 of the motor 1 is pot-shaped. In the present axial section it appears U-shaped. Here, the pinion shaft 2.3 is rotationally connected to the rotor 1.3 via a loothing. That is to say, located in the cross-piece 1.3.1 of the “U” is an interior toothing, while the pinion shaft displays a corresponding exterior toothing. The interior toothing and exterior toothing mesh with each other.

[0017] A different type of drive connection between the rotor 1.3 of the motor 1 and the pinion shaft 2.3 could also be produced. Thus, it is conceivable to design between these two elements not only a single, but rather two or several toothings with corresponding torque-transmitting elements, so that the rpm value of the rotor is translated upward or downward in the course of reaching the pinion shaft.

[0018] The rotor 1.3 is supported on the pump 2, more precisely on the hollow wheel 2.3 and the lateral discs 2.4, 2.5. 

1. Motor/pump unit; 1.1 with an electric motor (1); 1.2 with a pump (2); 1.3 the pump (2) is concentrically surrounded by the rotor/stator (1.1) of the motor; 1.4 the rotor (1.3) of the electric motor is U-shaped, viewed in an axial section; 1.5 the cross-piece of the “U” is provided, in the region of the common axis, with an interior toothing; 1.6 the shaft (2.2) of the pump (2) displays a pinion (2.1) that meshes with the interior toothing of the cross-piece of the “U”.
 2. Motor/pump unit according to claim 1, characterized by the fact that the rotor (1.3) of the electric motor surrounds the pump housing and is supported on the latter.
 3. Motor/pump unit according to one of the claims 1 or 2, characterized by the fact that the pump (2) is a hydropump.
 4. Motor/pump unit according to one of the claims 1 through 3, characterized by the fact that at least a part of the throughput of the operating medium of the pump (2) is used for cooling the motor.
 5. Motor/pump unit according to one of the claims 1 through 4, characterized through the following features: 5.1 located between the cross-piece of the “U” and the adjacent front wall of the motor housing is an open space; 5.2 the shaft (2.2) of the pump (2) projects into the free space and carries an impeller; 5.3 the impeller is designed and arranged such that it conveys cooling medium from the motor into the pump (2). 